First I would publish a list of suspected sources of nuclear weapons...you know Iran, North Korea, Russia. Then I would announce as policy, if America is attacked with nuclear weapons there will be no investigation, no handwringing about who did it. Number one on the list gets vaporized.
A group could get off the list by fessing up and cleaning out their weapons programs to OUR satisfaction. Naturally number two would escalate to number one.
See how they like a little game of hot potato with the loser holding the potato when the terrorists finally pop one.
Oh, one more thing. Anyone doesn't like the "preemption" can go to the top of the list.